Don't use MIB leafs that are not-accessible according to MIB

Add CiscoVTP test class

lib/SNMP/Info/CiscoVTP.pm

@@ -61,7 +61,6 @@ $VERSION = '3.54';
 %FUNCS = (
 
     # CISCO-VTP-MIB::managementDomainTable
-    'vtp_d_index'     => 'managementDomainIndex',
     'vtp_d_name'      => 'managementDomainName',
     'vtp_d_mode'      => 'managementDomainLocalMode',
     'vtp_d_rev'       => 'managementDomainConfigRevNumber',
@@ -780,10 +779,6 @@ Each bit represents a VLAN.  This is 3072 through 4095
 
 =over
 
-=item $vtp->vtp_d_index()
-
-(C<managementDomainIndex>)
-
 =item $vtp->vtp_d_name()
 
 (C<managementDomainName>)

xt/lib/Test/SNMP/Info/CiscoVTP.pm

@@ -0,0 +1,55 @@
+# Test::SNMP::Info::CiscoVTP
+#
+# Copyright (c) 2018 Eric Miller
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+#     * Redistributions of source code must retain the above copyright notice,
+#       this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+#     * Neither the name of the University of California, Santa Cruz nor the
+#       names of its contributors may be used to endorse or promote products
+#       derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+package Test::SNMP::Info::CiscoVTP;
+
+use Test::Class::Most parent => 'My::Test::Class';
+
+use SNMP::Info::CiscoVTP;
+
+# Remove this startup override once we have full method coverage
+sub startup : Tests(startup => 1) {
+  my $test = shift;
+  $test->SUPER::startup();
+
+  $test->todo_methods(1);
+}
+
+sub setup : Tests(setup) {
+  my $test = shift;
+  $test->SUPER::setup;
+
+  # Start with a common cache that will serve most tests
+  my $cache_data = {
+    'store' => {},
+  };
+  $test->{info}->cache($cache_data);
+}
+
+1;